/*
 * Copyright (c) 2020, Sensirion AG
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 *   list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright notice,
 *   this list of conditions and the following disclaimer in the documentation
 *   and/or other materials provided with the distribution.
 *
 * * Neither the name of Sensirion AG nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "sensirion_temperature_unit_conversion.h"

int32_t sensirion_celsius_to_fahrenheit(int32_t temperature_milli_celsius) {
    /* Conversion equivalent to: temperature_milli_celsius * 9.0/5.0 + 32000
     * Fixed Point: 9.0/5.0 * 2^12 = 7372.8
     * Using int32_t sized two's complement for negatives */
    return ((temperature_milli_celsius * 7373) >> 12) + 32000;
}

int32_t sensirion_fahrenheit_to_celsius(int32_t temperature_milli_fahrenheit) {
    /* Conversion equivalent to:
     * (temperature_milli_fahrenheit - 32000) * 5.0/9.0
     * Fixed Point: 5.0/9.0 * 2^10 = 568.9
     * Using int32_t sized two's complement for negatives */
    return ((temperature_milli_fahrenheit - 32000) * 569) >> 10;
}
